The present invention relates to a liquid sealed mount device for mounting a power plant on the car body.
A liquid sealed mount device is well known in which a mounting portion made of resin to be mounted on the side of a vibration generating portion such as an engine or a car body is injection molded in a rubber for damping (e.g., refer to patent document 1 and patent document 2).
[Patent Document 1]
JP-A-8-247208 (pages 3 to 5, FIGS. 1 and 3)
[Patent Document 2]
JP-A-2001-50331 (pages 3 and 4, FIGS. 1 and 2)
Referring to FIGS. 7A and 7B, FIGS. 1 and 3 of patent document 1 will be described below. And referring to FIGS. 8A and 7B, FIGS. 1 and 2 of patent document 2 will be described below.
FIGS. 7A and 7B are cross-sectional views showing the conventional liquid sealed mount device (conventional example 1) .
In FIG. 7A, a damping device 100 as the liquid sealed mount device comprises a bolt 101 attached on the engine side, a mounting member 104 including a top plate 102 and a tie arm 103, an elastic body 106 that is vulcanized and bonded on the mounting member 104, a support cylinder 107 made of resin and disposed to surround the elastic body 106, a partition member 111 for partitioning a liquid chamber 108 within the elastic body 106 into two chambers, a diaphragm 112 disposed outside the partition member 111, and a cap 113 press fit into an opening portion of the support cylinder 107 to fix the partition member 111 and the diaphragm 112.
Referring to FIG. 7B, a way for manufacturing the damping device 100 will be described.
First of all, the mounting member 104 is placed in a mold for vulcanization to vulcanize the elastic body 106 and bond the elastic body 106 to the mounting member 104.
Moreover, the elastic body 106 and the mounting member 104 are positioned within an injection mold, and molten resin material is injected into the mold, and molded while the support cylinder 107 is bonded with the elastic body 106.
And in the liquid, the partition member 111 and the diaphragm 112 are inserted into the liquid chamber 108 within the elastic body 106 and the support cylinder 107, and lastly the cap 113 is fitted into the inside of the support cylinder 107.
FIGS. 8A and 8B are cross-sectional views showing the conventional liquid sealed mount device (conventional example 2).
In FIG. 8A, a damping device 120 as the liquid sealed mount device comprises a top plate 121 attached on the engine side and a bolt shank 122 attached on the top plate 121, an elastic body 124 that is vulcanized and bonded on a lower face of the top plate 121 and a cylindrical insert fitting 123, an outer cylindrical member 126 disposed on the circumferential side of the insert fitting 123 and the elastic body 124, a partition member 127 and a diaphragm 128 disposed inside the insert fitting 123, and a lid member 131 disposed outside the diaphragm 128 and caulked and fixed by the insert fitting 123.
Referring to FIG. 8B, a way for manufacturing the damping device 120 will be described.
First of all, the top plate 121 and the insert fitting 123 are set within a mold for molding the elastic body.
Then, rubber in molten state is injected into the mold, and the elastic body 124 is vulcanized and bonded to the top plate 121 and the insert fitting 123.
Also, the top plate 121, the insert fitting 123 and the elastic body 124 are set within a mold for molding the outer cylindrical member. Then, resin in molten state is injected into the mold to form the outer cylindrical member 126 around the insert fitting 123.
And the partition member 127, the diaphragm 128 and the lid member 131 are inserted into the insert fitting 123, and the lid member 131 is caulked at the lower end portion of the insert fitting 123.
In FIG. 7, the metallic cap 113 is fitted into the opening portion of the support cylinder 107 made of resin to fix the partition member 111 and the diaphragm 112, and seal the liquid chamber 108. Therefore, the bonding strength between the support cylinder 107 and the cap 113 may be lowered due to a variation in press fit of the cap 113 into the support cylinder 107, a change with the passage of time, or a temperature variation, resulting in a lower sealing ability.
Thus, if the lid member 131 is caulked at the lower end portion of the insert fitting 123, as shown in FIG. 8, the above-mentioned problem is solved. However, in the technique of FIG. 8, the insert fitting 123 is extended from the upper to lower portion of the outer cylindrical member 126, and further to the portion under the outer cylindrical member 126, resulting in an increased weight of the damping device 120 as a whole, whereby there is less effect of reducing the weight by using the outer cylindrical member 126 made of resin in the damping device 120.
If the existent parts are made lighter, in addition to the use of resin, the weight of the damping device or the liquid sealed mount device is further reduced.